UK Broadband - Part 1 - Network Infrastructure

  • Monday, Feb 3, 2020

A lot of people come to me asking for advice about who the best broadband provider in the UK is. Before we can answer that question (which I’ll be going into in Part 2 ), first we need to look at how the UK’s communication networks are laid out.



Cable Types


The three different types of broadband cable: coaxial, twisted-pair, and fibre-optic

Take a look at the image above. These are the three most common types of cable that carry internet signals throughout the UK:

  • Coaxial Cable - these are descendants of the cables that traditionally carried video broadcast signals. In the UK, Virgin Media  use these cables to get from fibre optic cables (see below) that they lay in the street, to your house.

  • Twisted-Pair Cable - these are made of copper, and have often been in place for years. In the same way that Virgin use coaxial cable, BT Openreach  based providers (that is, almost every provider that isn’t Virgin Media) use these to get from the green cabinets you see in the street to your house (or if you are really unlucky and can’t even get “superfast” broadband, your whole connection will be based on these cables).

  • Fibre-Optic Cable - these transmit the data by transmitting light through the fibres inside. They are more expensive than coaxial and twisted-pair cables, but can carry much faster data speeds. Both BT Openreach and Virgin Media build their main network infrastructure using these cables - at least as far as the street outside your house. Only a minority of people in the UK actually get fibre optic cable all the way to their house (more on this coming up).

A word on the term “superfast”, a term which providers use a lot. In 2014 the government pledged that the UK would have “the best superfast broadband network in Europe” by 2015 and 90% of homes will be connected to superfast broadband by 2017. But the government’s definition of “superfast” broadband is only 24Mbps.

Such a low bar allows misleading headlines such as UK Superfast Broadband Coverage Slowly Edges to 96% .





The difference between ADSL, FTTC and FTTH broadbad connections

The large majority of residential broadband customers in the UK that use Virgin Media or BT Openreach have what’s called a “Fibre to the Cabinet (FTTC)" style connection. This means the fibre only goes as far as the green cabinets on the pavement (or under the street in the case of Virgin Media), and then the last leg between there and your house uses either twisted-pair cable (in the case of BT Openreach) or coaxial cable (in the case of Virgin Media).

At the time of writing, the maximum download speed offered by BT Openreach “fibre” (to the cabinet) is around 60-70Mbps, and the maximum download speed offered by Virgin Media “fibre” (to the street) is around 350Mbps. Uploads are much slower - to keep download speeds high, both providers cap upload speeds at somewhere around 20Mbps-50Mbps depending on your package (see here  to find out why). But neither fibre to the cabinet or fibre to the street are ideal.

The maximum speed you can get from a fibre to the cabinet connection can be limited by how far your property is from the physical cabinet/exchange  and also cabinet capacity . You might find that, even though in theory you should be able to get maximum speed, in reality it is much lower than this. Use Openreach’s availability checker  to check what the maxiumum speed you are supposed to be able to get is, then also cross reference this with a few Openreach providers (the MoneySavingExpert Broadband Checker Tool  is useful for this - put your details in and see what a few providers offer as your maximum speed).

Unfortunately a lot of people might find the maximum speed on offer is lower than the theoretical maximum 60-70Mbps download, 20Mbps upload speeds that FTTC should be able to give you, especially if your property is a long way from the cabinet/exchange and/or the cabinet is oversubscribed. Some of my customers are limited to a maximum of 20Mbps download and 4-5Mbps upload due to these issues.

In theory, Virgin’s fibre to the street should be more consistent - the coaxial cables they use to get from the street to your property aren’t affected by distance. However, a problem Virgin customers often face is that of contention ratio . Basically, the cheaper the package you are on, the more customers are sharing the connection at the street, meaning speeds can drop at peak times. Higher priced packages should suffer less from this, as there are less customers, and because you are paying more, the contention ratio should in theory be set to a lower number. However, in practice, I have found that all Virgin customers can suffer from slowdowns and outages if the area is very oversubscribed (and yes, that is most definitely the case in and around Catford!)

There are a handful of companies in the UK that offer “Fibre to the Home (FTTH)" connections (also referred to as “full-fibre”) for residential customers (for example, Hyperoptic ). These providers use fibre optic cables throughout their network, as well as using them all the way into your house. As a result, you are able to get simultaneous (also known as symmetric) download and upload speeds of 1000Mbps.

BT Openreach aims to provide 1000Mbps capable FTTH broadband to 4 million premises (homes and businesses) by March 2021 and then 15 million by around 2025 (Openreach Unveil 29 New UK Areas for FTTP Gigabit Broadband ). According to 2019 statistics , there are 27.8 million households in the UK (which doesn’t account for businesses). Even if that 27.8 million figure did include businesses, that means BT Openreach hopes that c15% of UK households will have FTTH by March 2021, and c.54% by “around 2025”.

(Update September 2020 - as expected, so far this FTTH rollout is an absolute disaster - BT broadband bills could reach £100,000 for rural users )



Why don’t Virgin Media and BT Openreach use fibre-optic cable all the way to your house?


A BT Openreach Engineer

Fibre optic cables are nowhere near as durable as coaxial and twisted-pair cables. As such, they really need to be laid inside plastic conduit tubing that is buried underground. Contrast this with Virgin Media, who often put coaxial cable into a plastic conduit and run it overground from the street to your house, or BT, who tend to just use existing twisted-pair cables to get from their green cabinets to your house. To get full fibre, it needs to have somewhere to go. That’s why you can only usually get full fibre in relatively new buildings, as it’s much easier to lay the cables during the building process.

An oft quoted article  tells the full story of why the UK is particularly behind. To summarise, basically BT was rolling out a true fibre optic network in the 1980s, but, because Margaret Thatcher thought a single supplier rolling out fibre-optic was anti-competitive, the rollout was halted. You can’t roll out a fibre optic network in bits; you have to do it as one continuous project as has been done in the countries that now have over 70% full-fibre coverage, like Spain, Portugal and Sweden:

According to the most recent figures from Ofcom, full-fibre broadband availability in the UK stands at 8%, with around 2.5 million properties covered. This is significantly lower than many other parts of the EU – where only Belgium, Cyprus and Greece have lower levels of full-fibre coverage than the UK, according to figures from the European Commission from 2018 which were published earlier this year. The figures indicate that those countries are joined by the UK and Germany as the only EU nations with full-fibre coverage under 10%. In contrast, the figures show that full-fibre coverage in Latvia stands at just under 90%, while Spain, Portugal and Sweden have coverage of 70% or higher. Further afield, countries such as Japan and South Korea both have full-fibre coverage of over 95%.

Source: How does UK’s full fibre broadband compare to other countries? - ITV News - 15th November 2019

What we’ve ended up with is pretty much a single supplier rolling out most of the UK’s fibre optic network anyway - BT Openreach. Only, all the space where the fibre optic cables could have been laid has been built on, and the rollout has to go in small stages.

NB - Virgin Media (previously called Telewest , then NTL  respectively) have been slowly building their own private fibre network for years, which is why they have historically had a lot less coverage than other providers. They’ve always been trying to find the gaps in BT’s network.

The latest grand master plan is to try to use 5G to plug the gaps in the infrastructure wirelessly - I feel this is a terrible plan; wires beat wireless all day long as they are much less subject to interference.

So, the UK is very behind the rest of the world when it comes to broadband. You are stuck choosing between a provider tied to BT Openreach’s FTTC network, Virgin Media or (if you are lucky), a full fibre provider such as Hyperoptic  (or BT Openreach in the less than 15% of households that are able to get a BT Openreach FTTH connection).

So how do you choose which one to go for? Let’s find out in Part 2 !